1. Field of the Invention
The present invention relates to a magnetic reading head including a magnetoresistance effect device and a magnetic recording apparatus equipped with the magnetic reading head.
2. Description of the Related Art
Heretofore, magnetic recording and reproducing apparatuses have been improved in recording density at a rate of more than 40% a year, and it is estimated that the recording density will reach the order of Tbit/in2 around the year of 2011 at the present rate of growth. Such a terabit-level magnetic recording apparatus needs to be equipped with a magnetic writing and reading head with higher output and higher resolution than ever.
As an elemental technique for an existing magnetic recording and reproducing apparatus, a current perpendicular to plane giant magneto resistance (CPP-GMR) head and a tunneling magneto resistance (TMR) head have been proposed. In each of these spin valve reading heads, a sense current is caused to flow perpendicular to the stacked-layer surface thereof, and a leakage magnetic field from a medium is detected by using a magnetic material (free layer). Specifically, each spin valve reading head shows a resistance change based on a magnetization direction of the free layer relative to the fixed magnetization direction of a magnetic material (pinned layer).